Volume 21, Number 5
1997

Literature

Note: The classification number that follows each entry is there
to help the editor arrange, file and find the citations. When the
publisher's address is not given, it can usually be found in the
list of Useful Addresses that is mailed out yearly to subscribers.

"Effect of Paper Alkaline Reserve on the Chemical Stability of
Acetate Base Sheet Film," by Jean-Louis Bigourdan, Peter Z.
Adelstein, and James M. Reilly. Topics in Photographic
Preservation v.7, 1997, p. 43-54. That issue of
Topics is available from the American Institute for
Conservation for $15 + $3.

This is a report of research funded by the NEH and the Institut
Français de Restauration des Oeuvres d'Art, Paris. It
answers a number of questions that people have been asking for
years.

First, do buffered paper enclosures slow down the development of
the "vinegar syndrome" (degradation of acetate film base)? Answer:
Hardly at all, because calcium carbonate is so slow to react with
the acetic acid given off by the film. It did react fairly rapidly
over the first two weeks, but more than half of the alkaline reserve
was still left at the end of 50 days' exposure, coexisting with the
free acid in the fiber of the paper.

Second, are buffered papers more effective acid receptors than
plain papers? Answer: Yes. But the practical impact on the film
is limited. Third: Do paper enclosures slow the "infection" of
sound film by degrading film? Answer: No.

Fourth: Which is better: Paper (buffered or nonbuffered) or
plastic envelopes for sheet film? Answer: Neither offers an
advantage. Question: Then what shall we do about our acetate film
collections? Answer: "Segregation of degrading objects,
re-housing, and efficient ventilation are considered important for
collection management. The control of temperature and relative
humidity remains the most effective and quantified preservation
strategy for cellulose acetate film collections." (3F2)

"Shandon Xylene Substitute in Document Examinations," by Gary
Licht and Jerry Brown, Iowa Division of Criminal Investigation
Laboratory, Wallace Building, Des Moines, IA 50319-0041. This
solvent is marketed as a noncarcinogenic substitute for xylenes. It
is nondestructive to inks, paper or plastics, less volatile than
xylene, and is only a weak solvent of correction fluids. The
authors use it mainly to make paper translucent, to allow
obliterated writings to be read through the back side of the page,
and to permit IR examinations through the paper. It does not affect
indented writings, and it evaporates without leaving any odor,
discoloration or distortion. (3B2.71)